# Questions tagged [simulation]

Simulation is the imitation of the operation of a real-world process or system over time.

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### Issues with modeling pulses in a very simple system of DAEs

Bug introduced in 10.4.1 or earlier and fixed in 11.0.0 Bug has been confirmed by WRI [Case:3594387]: It does appear that the NDSolve function is not behaving properly in this case and an incident ...
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### Calculate $\pi$ using Monte Carlo methods

I know that we can have an estimate of $\pi$ using Monte Carlo methods. I know that we make a huge loop and each time we take randomly two numbers in the range [0,1] and calculate the number of ...
457 views

### Simulation with two random walkers on a lattice with periodic boundaries

I am having some difficulties implementing a Monte Carlo simulation in order to compare the results to analytical calculations. The following code simulates a case with one random walker and a ...
173 views

### Periodic boundary conditions for two walkers

For some reason I'm getting infinite loops most of the time i run this. Perhaps the periodic boundary conditions are wrong. Seems like the probability of the two positions to be the same is extremely ...
405 views

### Simulating a “Coin Tossing” Game

i was wondering if i could simulate the following Coin-tossing-game in Mathematica: Two Persons are playing "Coin-tossing" against each other. If one wins, he gives one Dollar to the other. Game ...
757 views

### How to model wooden joints with mathematica's FEM?

This is a dovetail joint: and I'd like to see the stresses and deformation on the joint.I haven't seen any modeling of disconnected regions with FEM, only connected regions, so I'm curious if you can ...
513 views

### Beam deformation due to localized force distribution

I would like to simulate the deformation of a beam which is fixed on one end and has some localized forces applied along the top. I have been inspired by this Mathematica example: http://www....
874 views

### How to add moon to orbit Earth that Orbit Sun

I want to add moon(Blue) that orbiting earth(Red). while Earth is orbiting Sun. this is my code so far that consist of earth, sun and moon. how to write a code so that Moon is orbiting earth instead ...
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### Interstellar Image Effects

I'd like to know how to create this type of gravitational lensing effect in an image (here are some star fields from the hubble) "I wrote down the equations and I tested them in Mathematica by ...
817 views

### How to see phase difference of two pendulum

i want to see the simulation of two uncoupled Simple Harmonic Motion (SHM) pendulum with different Lengths and released at different initial displacement angles. in this case adding one more pendulum ...
676 views

### How to make A simulation of 2-Dimensional Projectiles

Lets say two cannon is fired at different initial position, initial angle and initial speed. let say initial speed,angle and position for projectile 1= ...
428 views

### Simulating a Wave Pulse

How to construct a code that superimpose n=10 one dimensional sinuisodal waves. each with an angular frequency ...
416 views

### How to do multi-agent modeling?

There are tons of examples here: http://demonstrations.wolfram.com/topic.html?topic=multi-agent+modeling&limit=20 But I been unable to find a good guide explaining what is the recommended ...
322 views

### Ball rotating in a Turntable

I made a turntable to make some experiments and make some studies about Coriolis and Euler forces acting in different frames of reference. ...
3k views

### How to make a Cahn–Hilliard model GIF

The question derived from @Jason B 's answer.I wanna make it but don't how to do.But we can get some rule about the GIF The change of the total pixel is very small. ...
364 views

### 3D orbits of moons around their respective planets

I have seen a lot of solar system models (both animated and not), but I am trying to replicate the same thing with moons. Either just one planet and its lunar system or the our whole solar system with ...
1k views

### How best to simulate n-body systems in a functional way?

I want to simulate a N-body system in the most functional way possible. The system I'm modeling are metallic colloidal particles in a solution of peroxide water, as here http://arxiv.org/pdf/1502....
506 views

### Generate a simulated covariance matrix

I am working on a problem where one of the input variables is the level of covariance between the entries in a particular matrix. To simulate this problem in Mathematica, I will need to feed my code ...
384 views

### Confining/Periodic boundary conditions implementation for 2D Random Walker

I am new to Mathematica, and am having trouble implementing confining boundary conditions for a random walk simulation confining the walker to a pre-defined region (periodic boundary conditions would ...
339 views

### Battery charge simulation not clipping properly as it iterates

My code for simulating a batterylevel-state throughout a year in 15min-steps doesn't work. There is a certain list-inputs which simulates the charge state and the batterylevel-state, additionally ...
678 views

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### Evaluation problems with NDSolve using the fixed step ExplicitEuler-Method

Motivation I am using Mathematica to implement System Dynamics (SD) models, e.g. differential equation models as applied to management/economic problems following the "methodology" of Jay W. ...
408 views

### Simulation of LogNormal process for an asset pricing

I'm new to Mathematica programming, so forgive my rather unsophisticated question. I need to simulate 5000 "walks" of a process value (of a stock) that starts from its current value, at ...
101 views

### How to deal with Part in a function?

I need to iterate several functions such as {3 x[]^2 + x[], x[], x[]}, {Exp[x[]], x[], x[], x[]},etc. ...
130 views

### My simulation is not never finishing and it is taking so much time?

I am running simple code which involves calculation of two first order differential equations.It is taking so much time and i am unable to get the results as the simulation is never finishing. ...
191 views

### How to speed up a system simulation?

I need to simulate a series of nonlinear (and linear) with thousands of state variables. Here is a simple linear example ...
87 views

### How would I go about simulating conditional random birth 100 times?

So I have the following scenario: Assume you have this organism that reproduces by itself. An organism either reproduces 0, 1, 2, or 3 organisms at a time. Assume they're asexual and reproduce only ...
950 views

### Random polyhedra walk

I would like to recreate ssch's random polyhedra random walk, which he posted in the chat. For convenience here it is again: This is my best attempt so far: You can download the notebook with the ...
1k views

### How to define a distribution that 90% of the time gives me 0?

This maybe a simple question, but I am just stuck with it. I want to do some simulation, say with 0.9 probability, I get a 1, and 0.1 probability get a 0. How would I do that? Where should I start? ...
151 views

### Adding extinction factor to Monte Carlo analysis

I'm looking to add an absorption component to this Monte Carlo analysis, essentially I want there to be a 1% chance that a photon gets absorbed at each event as it travels through the medium, once the ...
601 views

### Random walk using Module [closed]

I want to create a random walk using Module. The walk start at {0, 0}. At every step, x ...
1k views

### Simulate random data with correlation

I would like to simulate some random data e.g. between 0 and 1, but with a given correlation. In other words some data where the correlation between two datasets is e.g. a constant or within a give ...
205 views

### Simulation of the semicircle Wigner Theorem

Let's begin with some termes: For $1\le i<j<\infty$ let $X_{i,j}$ be independant and indentically distributed (i.i.d) real random variables with mean $0$ and variance $1$ and set \$X_{j,i}=X_{...
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### How to set up a simple Monte Carlo simulation?

there is a 1% chance that there will be a scattering event, if there is a scattering event the direction of scattering will be determined by a random sample of the custom[a_] function and if there is ...
143 views

### Find maximum Log likelihood for repeated random variates

I have the following code ...
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### Computational Bayesian analysis in Mathematica: Any plans to develop MCMC?

Does anyone know if there are any plans to develop an MCMC capability in Mathematica? My reasoning for asking is that as it stands, I can't seem to find any 'out-of-the-box' functions/capabilities ...
406 views

### Simulate a polygon bouncing with collision detection inside a circle/polygon

Simulate a polygon bouncing with collision detection inside a circle/polygon. the example can be see in help page by searching WhenEvent; ...
398 views

### Solving 2-D Mechanical Systems

I'm trying to use Mathematica to solve a particular 2-d mechanical system. The system comes from "DESIGN AND OPTIMIZATION OF AN EIGHT-BAR LEGGED WALKING MECHANISM IMITATING A KINETIC SCULPTURE, “WIND ...
161 views

### How to control pedestrians to enter the simulation region with random functions?

I am working on simulating crowds of a cross-typed region, given that pedestrians entering from 4 gates of north, east, west and south, ...
96 views

### How can I use manipulate on multiple lists within a function?

So I have my N-Body Problem set up like so, and I can plot it in ListPointPlot3D, but I cannot figure out how to stick this into a manipulate function. ...
I am trying to do a Monte Carlo area calculation for an irregular area defined by: $$0 \le x \le 1, 10 \le y \le 13, y \ge 12 \cos(x), y \ge 10 + x^3$$ I used the code with modifications (so I can ...